For the permits, many many people don't apply for a permit if the work is done on the inside of the home. This is something I have found out through my 15 years in real estate. You can check with the city of Dallas on that particular home, again if you are looking within the city of Dallas. Here is a link for contact info. http://www.dallascityhall.com/building_inspection/index.html
I'll be happy to assist if you need help. Don't hesitate to contact me.
All the Best!!!